Resistance of a Wire

In this investigation, we will be studying the resistance of a wire. The resistance of a wire depends on many factors, some of these include;

Length of the wire

Thickness (diameter) of the wire

The material of the wire

The temperature at which the wire is kept

Resistance can be explained as opposing the flow of electric current around the circuit so energy is required to push the charged particles around the circuits. This will then cause electrons to take an obstructive path and collide with protons which will resist against them, therefore, resistance is present. From previous research I can say that the longer the wire, the higher the amount of resistance. We can back this up as there will be more atoms in more metal so there will be a higher chance of them colliding to cause resistance.

The equipment needed in order to conduct this experiment is as follows; we will need a length of constantan (28 SWG) wire spread over a metre rule, a power supply, approximately 7 connecting wires, 2 crocodile clips and 2 multi-meters which can be used as voltmeter and ammeter functions. The connecting wires will be connected to the power supply and the 2 crocodile clips.

I first connected the connecting wires to the power supply and started building the circuit. I connected the multi-meters to the power supply, and then from there, I connected the wires from the multi-meters to the crocodile clips. The multi-meters were then switched onto the required function and I was ready to record results. To begin the test, the power supply was switched on and set at a constant power of 2 volts. I then had to keep one of the crocodile clips at the 0cm mark of the metre and the other was moved to each 10cm mark through the metre (10cm, 20cm, 30cm and so on). When the crocodile clip was connected at a 10cm mark, I was to take the reading

From the results and graphs that I have got from the experiments, I have found that my prediction was correct, the longer the wire, the higher the resistance. Our experiment went to plan in terms of the reliability and expectation but if there were abnormalities in the results there could be many explanations for these. They may include:

The temperature of the wire when the reading is taken.

The condition of the wire, a worn out piece of wire may affect the flow of current.

Damages in other pieces of equipment.

Power Supply.

Multi-meter setting.

When conducting the experiments there were no anomalous results found so our graphs did not display any odd patterns.